Radioactive Contamination EH perspective Wendy Shakespeare Contaminated Land Officer Fareham Borough Council
Overview • Fareham Borough Council experiences • HMS Daedalus • Similarities & Differences with other con land investigations • Quick look at RCLEA • Development – Tips to make development run more smoothly • Watchpoints Fareham Borough Council
Fareham Borough Council Experiences • Many military and ex-military sites • 2011 MOD released a list of 15 radioactive contaminated sites in UK HMS Daedalus DARA Gosport Guardian (2011) http://www.theguardian.com/environment/2011/dec/20/mod-radioactive-world-war-two Fareham Borough Council
HMS Daedalus • 1917 RNAS Lee on Solent • Significant role during 1 st and 2 nd World Wars • Decommissioned 1996 • Purchased by public sector 1996 • 2012 Enterprise Zone Fareham Borough Council
HMS Daedalus • 2011 Outline planning application for retail, employments, residential, community use, hotel, clubhouse, allotments, public open space and landscaping – Approved • 2011-present – numerous individual applications under the outline Fareham Borough Council
HMS Daedalus – Radioactivity • Desk Study • Gap Analysis 2001 • Radiological survey 1996 of Fire Training Ground • Remediation exercise of FTG – confirmation 1998 • Phase 2 radiological investigation 2003 • Surface walkover 2004 & 2005 (100% coverage accessible areas GPS) • Intrusive investigation 2005 (69 trial pits) Fareham Borough Council
HMS Daedalus • Radium 226 • Max activity of 4 Bq/g • Max contact dose of 1.3µSv/h • 11.39mSv/yr Fareham Borough Council
Dose Levels - National Background and Part IIa Background PHE – average UK radiation dose is 2.7 mSv/yr Part IIa • An effective dose of 3 mSv/yr • An equivalent dose to lens of eye 15 mSv/yr • An equivalent dose to skin of 50 mSv/yr Fareham Borough Council
HMS Daedalus Recommendations of LQS submitted with Outline Application • Remedial target of 0.3mSv/yr (residential uses) • 0.34Bq/g No longer appropriate – RCLEA revised 2011 • 3 mSv/y - RSGV is 35Bq/kg or 0.035Bq/g • 2.6 mSv/y - concentration on site of 30Bq/kg or 0.03Bq/g Fareham Borough Council
Similarities • Process same - Desk study, site investigation, risk assessment (RCLEA), remediation, validation. • Soil sampling, soil gas sampling (esp Radon), water sampling, indoor air monitoring • Non intrusive & Intrusive survey methods • Take account of background concentrations Fareham Borough Council
Similarities • Exposure pathways – inhalation of soil gas (Rn-222), soil ingestion, ingestion of vegetables and soil on vegetables (internal radiation), • Application of principles of BS10175: 2011+ A1:2013 and BS 5930:1999 • Minimising cross contamination during SI – spoil heaps, purged water • ALARP applies in risk assessment and remediation Fareham Borough Council
Differences • Exposure pathways – External whole body irradiation, skin external irradiation (RCLEA) • Types of equipment used – scintillation detectors • Waste Disposal – Environmental permitting (need EA permission in place before start digging) Fareham Borough Council
Common Contaminants DEFRA (2006) Industry Profile Industrial activities which have used material containing radioactivity http://uk.practicallaw.com/cs/Satellite?blobcol=urldata&blobheader=application%2Fpdf&blobke y=id&blobtable=MungoBlobs&blobwhere=1247264181979&ssbinary=true Fareham Borough Council
Development Tips For LA • Speak to the specialist advisor undertaking the work – what equipment, limitations – detection, background concentrations, detection limits, size of area surveyed and size of anomalies (grid size), sampling • Speak to the EA – especially about permitting requirements https://www.gov.uk/government/collections/radioactive-substances-regulation-for-non-nuclear- sites RSR.Rotherham2.NE@environment-agency.gov.uk Fareham Borough Council
Development • Speak to PHE https://www.phe-protectionservices.org.uk/ 01235 825313 • Refer to guidance – Ciria W30 good practice guidance for site characterisation, RCLEA CLR 12, 13 & 14 • Use Soil Guideline Values in RCLEA (CLR 13) • Use RCLEA to generate doses if you know activity on site. Fareham Borough Council
Soil Guideline Values For Single Radionuclide CLR 13 Appendix B Fareham Borough Council
Nuclear Industry Group for Land Quality (2011) Qualitative risk assessment for land contamination, including radioactive contamination
Development Tips for Developers • Employ specialist Radiation Consultant – consider if need RPA • Arrange meeting with LA environmental health & planning prior to works starting • Get consultants to review any previous radiological surveys • Undertake new radiological surveys well in advance of starting on site • Make a note of areas that cannot be surveyed and agree when this will be surveyed • Maintain dialogue through regular site meetings • Consider contamination at depth • All surveys have limitations – discovery strategy, toolbox talks and inform LA of found items – speak to consultant again Fareham Borough Council
Watchpoints • Areas not surveyed e.g. surface concrete, roads • Surveyed at depth? • Correct material surveyed – not imported materials • Radionuclides not picked up by the equipment • Hiring of scintillation detectors and self assessment • Units of measurement in assessment and conversions between units of measurement • Moving soil/ reduced digs/ drainage excavations – changes to soil profile Fareham Borough Council
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